This invention relates to a fuel system, and particularly to a fuel-transfer system. More particularly, this invention relates to a vehicle filler neck and a valve for regulating flow of liquid fuel and fuel vapor between the vehicle filler neck and a vehicle fuel tank.
A filler neck is a tube which conducts liquid fuel from a fuel-dispensing pump nozzle to an interior fuel-storage region in a fuel tank. Although an opened passageway through the filler neck into the fuel tank is needed during refueling to conduct liquid fuel from the pump nozzle into the fuel tank, it is desirable to close the filler neck at other times to block discharge of liquid fuel and fuel vapor from the fuel tank through the filler neck. However, if the pressure of fuel vapor in the fuel tank reaches a predetermined level, it is desirable to relieve the pressure in the fuel tank by venting pressurized fuel vapor from the fuel tank to the filler neck for discharge therefrom.
On occasion, it is necessary for mechanics to remove liquid fuel from the fuel tank during maintenance or repair of a vehicle. To remove the liquid fuel, a mechanic or other individual often inserts a siphon tube through the filler neck into the fuel tank and siphons or otherwise pumps the liquid fuel from the fuel tank.
According to the present invention, a fuel-transfer system includes a fuel tank and a fuel conductor coupled to the fuel tank. The fuel conductor includes a housing having a fuel-transfer channel and a diverter valve positioned to lie in the fuel-transfer channel. The diverter valve is movable from a first position blocking the flow of fuel vapor or liquid fuel through the channel to a second position permitting the flow of fuel vapor or liquid fuel through the channel. The diverter valve includes a guide surface adapted to intercept and divert a siphon tube moving in a fuel tank filler neck and guide it toward a bottom wall of the fuel tank.
In preferred embodiments, the diverter valve further includes a pressure-relief valve. The pressure-relief valve is movable between a first position blocking the flow of fuel vapor through the diverter valve to a second position permitting the flow of fuel vapor through the diverter valve and the fuel-transfer system. The pressure-relief valve moves to the second position when fuel vapor pressure levels in the fuel tank reach a predetermined level to relieve pressure in the fuel tank.
Additional features of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.